The invention relates generally to devices for cleaning welding torch nozzles, particularly those welding torches which employ wire-fed welding rods through the center of the torch.
The invention relates more specifically to a wire feed welding torch system used in conjunction with an automatic manipulator, or welding robot.
Wire feed welding torches of the TIG and MIG type employ a device for welding which consists generally of a tubular body through the center of which is fed the welding rod from a wire spool and inert gases are also fed through the body of the torch to provide a suitable welding environment. The torch body is fitted with a torch nozzle at its forward end, and the nozzle consists of a generally tubular device having a hollow inside diameter and having its outer diameter tapered to a converging end point. The nozzle is also fitted with gas outlet slots around its diameter. The nozzle or "shroud" can accumulate weld spatter around its inside surface, and the weld spatter may block the gas outlet ports and possibly interfere with the wire feed movement.
In its known in the art to sometimes apply a spray of anti-spatter compound to the inside of the welding nozzle to prevent spatter build-up. However, build-up will usually occur as time progresses.
It therefore becomes necessary to provide for some means of scraping away and removing the weld spatter from the inside of the welding nozzle of a welding robot. Most welding robots have the ability to mve the end effector and its associated welding torch through a variety of spatial orientations, so a remotely located device for removing weld spatter presents no problem of access.
A popular nozzle cleaner for robotic welding is found in the prior art devices manufactured by MTE Binzel (UK) Ltd., and illustrated in the 12 page catalogue of that company. Specifically, on page 7 of that catalogue, a nozzle cleaner for robotic welding is depicted, wherein a base frame carries a vertically oriented tube. The tube is spring-mounted to the base frame so that the tube is compliant and movable through multi-degrees of freedom. The tube carries an end sleeve at its topmost end which is spring-loaded in an axial direction into the tube. The end sleeve has a bellmouthed hole at its topmost end, which is capable of receiving the convergent outersurface of a robot welding nozzle. The lower part of the vertical tube carries a rotary motor attached to a reamer spring extending upward through the tube and end sleeve. The reamer spring performs the function of a helical auger (of the type used in augering plumbing lines). At desired clean out times, the robot presents its nozzle to the nozzle cleaner and upon engaging the bellmouthed sleeve, the reamer drive motor is switched on and causes the rotary reamer to auger out the inside of the nozzle. The Binzel cleaner is very compliant, thus accommodating positional inaccuracies in the robot device. Further, large cleaner cutting forces are not experienced by the robot welding tool, which is cantilevered from the robot base and not otherwise supported. The spring auger of the Binzel device permits removed weld spatter to fall into the spring mechanism to clear the nozzle. After the nozzle has been reamed, it is lifted from the nozzle cleaner and a blast of air is provided to clear the nozzle of any remaining spatter debris. Many Binzel devices also provide for an air-misted antispatter compound to be sprayed into the weld nozzle.
Applicant has found that for many applications, the accumulated weld spatter is resistant to dislodging by means of the relatively flimsy spring auger. Thus, it has been necessary for applicant to create a more positive and rigid nozzle cleaner for robotic welding. Applicant has obviated the difficulties inherent in the prior art device, by creation of a relatively rigid assembly which provides for clamping of a proximally positioned weld nozzle and, after clamping the nozzle into the device, a substantially rigid reamer can be moved through the interior of the weld nozzle to remove accumulated spatter.
It is therefore an object of the present invention, to provide for a substantially rigid and more reliable means for removing weld spatter from the interior of a robotic welding nozzle.